scholarly journals Eave and swarm collections prove effective for biased captures of male Anopheles gambiae mosquitoes in Uganda

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Krystal Birungi ◽  
Danspaid P. Mabuka ◽  
Victor Balyesima ◽  
Annet Namukwaya ◽  
Elinor W. Chemoges ◽  
...  
Keyword(s):  
Mosquito Control ◽  
Wet Season ◽  
Resting Sites ◽  
Mosquito Sampling ◽  
Mark Release Recapture ◽  
Mosquito Collection ◽  
Mosquito Ecology ◽  
Males And Females ◽  
Study Sites ◽  
Male Mosquito

Abstract Background Traditional malaria vector sampling techniques bias collections towards female mosquitoes. Comprehensive understanding of vector dynamics requires balanced vector sampling of both males and females. Male mosquito sampling is also necessary for population size estimations by male-based mark-release-recapture (MRR) studies and for developing innovations in mosquito control, such as the male-targeted sterile insect technique and other genetic modification approaches. This study evaluated a range of collection methods which show promise in providing a more equal, or even male-biased, sex representation in the sample. Results Swarms were found at all study sites and were more abundant and larger at the peak of the wet season. Swarm sampling caught the most males, but when man/hour effort was factored in, sampling of eaves by aspiration was the more efficient method and also provided a representative sample of females. Grass-roofed houses were the most productive for eave collections. Overall few mosquitoes were caught with artificial resting traps (clay pots and buckets), although these sampling methods performed better at the start of the wet season than at its peak, possibly because of changes in mosquito ecology and an increased availability of natural resting sites later in the season. Aspiration of bushes was more productive at the peak of the wet season than at the start. Conclusions The results of this study demonstrate that eave aspiration was an efficient and useful male mosquito collection method at the study sites and a potentially powerful aid for swarm location and MRR studies. The methods evaluated may together deliver more sex-balanced mosquito captures and can be used in various combinations depending on the aims and ecological parameters of a given study.

scholarly journals The cost of associating with males for Bornean and Sumatran female orangutans: a hidden form of sexual conflict?

2020 ◽  
Vol 75 (1) ◽  
Author(s):  
Julia A. Kunz ◽  
Guilhem J. Duvot ◽  
Maria A. van Noordwijk ◽  
Erik P. Willems ◽  
Manuela Townsend ◽  
...  
Keyword(s):  
Sexual Conflict ◽  
Sexual Coercion ◽  
High Association ◽  
Sexual Swellings ◽  
Fecal Cortisol ◽  
Habitat Productivity ◽  
Pongo Pygmaeus Wurmbii ◽  
Males And Females ◽  
Study Sites ◽  
The Cost

Abstract Sexual coercion, in the form of forced copulations, is relatively frequently observed in orangutans and generally attributed to their semi-solitary lifestyle. High ecological costs of association for females may be responsible for this lifestyle and may have prevented the evolution of morphological fertility indicators (e.g., sexual swellings), which would attract (male) associates. Therefore, sexual conflict may arise not only about mating per se but also about associations, because males may benefit from associations with females to monitor their reproductive state and attempt to monopolize their sexual activities. Here, we evaluate association patterns and costs for females when associating with both males and females of two different orangutan species at two study sites: Suaq, Sumatra (Pongo abelii), and Tuanan, Borneo (Pongo pygmaeus wurmbii). Female association frequency with both males and females was higher in the Sumatran population, living in more productive habitat. Accordingly, we found that the cost of association, in terms of reduced feeding to moving ratio and increased time being active, is higher in the less sociable Bornean population. Males generally initiated and maintained such costly associations with females, and prolonged associations with males led to increased female fecal cortisol metabolite (FCM) levels at Tuanan, the Bornean population. We conclude that male-maintained associations are an expression of sexual conflict in orangutans, at least at Tuanan. For females, this cost of association may be responsible for the lack of sexual signaling, while needing to confuse paternity. Significance statement Socioecological theory predicts a trade-off between the benefits of sociality and the ecological costs of increased feeding competition. Orangutans’ semi-solitary lifestyle has been attributed to the combination of high association costs and low predation risk. Previous work revealed a positive correlation between association frequencies and habitat productivity, but did not measure the costs of association. In this comparative study, we show that females likely incur costs from involuntary, male-maintained associations, especially when they last for several days and particularly in the population characterized by lower association frequencies. Association maintenance therefore qualifies as another expression of sexual conflict in orangutans, and especially prolonged, male-maintained associations may qualify as an indirect form of sexual coercion.

scholarly journals Rainfall as a significant contributing factor to butterfly seasonality along a climatic gradient in the neotropics

2019 ◽  
Author(s):  
María F. Checa ◽  
Elisa Levy ◽  
Jaqueline Rodriguez ◽  
Keith Willmott
Keyword(s):  
Temporal Dynamics ◽  
Dry Forest ◽  
Butterfly Species ◽  
Climatic Gradient ◽  
Wet Season ◽  
Precipitation Regimes ◽  
Butterfly Communities ◽  
Set Up ◽  
Study Sites ◽  
Seasonal Forests

AbstractWe analyzed the dynamics of multi-species butterfly communities along a climatic gradient with varying precipitation regimes for three consecutive years, and determine how climatic variables associate with observed butterfly seasonality. To provide a baseline for future studies of how climate change might affect these butterfly populations, we additionally explored the role of butterfly seasonality as a potential contributing factor for their susceptibility to climate variation. As far as we know, this represents the first study that simultaneously sampled and described seasonality patterns of tropical butterfly communities across ecosystems with varying climatic seasonality. A 3-year survey was carried out at three sites (i.e., wet, transition and dry forests) across a climatic gradient in western Ecuador. Butterflies were sampled using traps baited with rotting banana and prawn every two months from Nov 2010 to Sep 2013. Traps were set up at two heights, in the understory and canopy. In total, 7046 individuals of 212 species were sampled over 180 sampling days.Butterfly communities exhibited conspicuous intra and inter-annual variation in temporal dynamics with certain elements (e.g., maximum abundance recorded) of seasonality patterns likely synchronized in seasonal forests (i.e., transition and dry forest) across years but not in aseasonal forests (i.e., wet forest). In addition, the highest numbers of species and individuals occurred during the wet season across all study sites and years; indeed, rainfall was significantly positively associated with temporal abundance. Likewise, butterfly species displaying stronger seasonality were significantly associated with higher rainfall periods in seasonal forests. Variation in precipitation regimes might significantly affect more seasonal species.

scholarly journals An Investigation into Marmot Migration in Grand Teton National Park

1996 ◽  
Vol 20 ◽  
pp. 78-82
Author(s):  
George Montopoli ◽  
Nick Visser ◽  
Hank Harlow
Keyword(s):  
National Park ◽  
Movement Patterns ◽  
Snow Melt ◽  
Marmota Flaviventris ◽  
Long Distance ◽  
The North ◽  
North Fork ◽  
Males And Females ◽  
Study Sites ◽  
Long Distance Movement

In 1994 and 1995, a high abundant winter snowfall at higher elevations appeared to result in long distance movement patterns by yellow-bellied marmot (Marmota flaviventris) over snow to lower, snowfree elevations where food was more available. As the snow melted and food became abundant, the marmots return to higher altitudes. In 1996, we continued to investigate the potential for migrational movements, by studying two study sites at different elevations in the North Fork of Cascade Canyon. Four marmots at each site were implanted with intraperitoneal tracking transmitters. Of eight marmots that were equipped with intraperitoneal transmitters, six demonstrated significant movements of greater than 0.5 km, one did not, and one most likely died as a result of predation before any movement could be observed. Of the six that demonstrated significant movements within the canyon, only one moved distances greater than 1 km. Marmots, after emerging from hibernation, migrated down canyon to snowfree areas as they become available. With progressive snow melt, most marmots move upward to higher elevations, but not to the extent originally expected. Instead, they moved to the first available habitat where food was obtainable, and other (dominant) marmots accepted their presence. This movement is exhibited in both males and females, yearlings and adults, and melanistic and normal colored marmots.

scholarly journals The Morphological Measurement Variations of Periophthalmus chrysospilos along the Coastline in the Mekong Delta

2021 ◽  
Author(s):  
Le Trung Hieu ◽  
Dinh Minh Quang ◽  
Hua Van U ◽  
Nguyen Huu Duc Ton
Keyword(s):  
Morphological Variation ◽  
Body Height ◽  
Mekong Delta ◽  
Wet Season ◽  
Morphological Variations ◽  
Total Length ◽  
Fish Samples ◽  
Eye Diameter ◽  
And Gender ◽  
Study Sites

This study provided data on morphological variation in Periophthalmus chrysospilos. The study was carried out in four provinces from Tra Vinh to Soc Trang, Bac Lieu and Ca Mau. Fish samples were collected by hand-catching over 12 months from April 2020 to March 2021. Analysed results of a collection of 1,031 individuals (508 females and 523 males) showed that the total length (TL) and weight (W) of the female Periophthalmus chrysospilos were higher than that of the male, higher in the wet season than in the dry season and gradually increased from Tra Vinh to Ca Mau. Besides, the total length and weight of fish were also influenced by the interaction of season ´ site and gender ´ site. In addition, the morphological variation of this species such as eye diameter (ED), eye distance (DE), body height (BD), head length (HL) and taxonomic ratios such as HL/TL, BD/TL, ED/HL, DE/HL was gender, seasonal fluctuations and study sites. These morphological variations and ratios were also influenced by interactions season ´ site interactions. The findings contributed further information to fish identification and the ecological adaptation understanding of this species.

Diurnal resting sites of the nocturnal dasyurid marsupial Sminthopsis douglasi in Bladensburg National Park, Queensland

2017 ◽  
Vol 39 (1) ◽  
pp. 121 ◽  
Author(s):  
P. A. Woolley
Keyword(s):  
National Park ◽  
Climatic Factors ◽  
Short Term ◽  
Term Study ◽  
Resting Sites ◽  
Short Term Study ◽  
Males And Females

An attempt has been made to determine where Julia Creek dunnarts (Sminthopsis douglasi), small nocturnal dasyurid marsupials, rest during the day under differing seasonal conditions. A short-term study was carried out in Bladensburg National Park, near the southern edge of its known distribution on the Mitchell grass downs in Queensland. Radio-collared individuals were located in cracks and holes. None of the males and females (including one with young in the pouch) were found to use the same resting site over periods of up to nine days, suggesting that they may be nomadic. Climatic factors may have affected the size of the dunnart population over the course of the study.

Reproduction in the curly-tailed lizard Leiocephalus psammodromus from the Caicos Islands

1993 ◽  
Vol 71 (11) ◽  
pp. 2147-2151 ◽  
Author(s):  
Geoffrey R. Smith ◽  
John B. Iverson
Keyword(s):  
West Indies ◽  
Fat Body ◽  
Size Structure ◽  
Egg Laying ◽  
Egg Mass ◽  
British West Indies ◽  
Female Reproduction ◽  
Wet Season ◽  
Males And Females ◽  
Fat Body Mass

Reproduction and population structure were examined for the curly-tailed lizard Leiocephalus psammodromus from the Caicos Islands, British West Indies, from 1973 to 1978. Females and males mature at about 65–70 and 75–80 mm snout–vent length, respectively, and at about 1.5–2 years of age. Both male and female reproduction were seasonal, with egg-laying beginning late in the dry season (late April) and ending well into the wet season (September), with hatching during the wet season (late June to December). Multiple annual clutches are probably produced. Clutch size was typically two eggs (mean = 1.72 for 42 clutches). Eggs (preserved) averaged 19.9 × 9.2 mm, and mean preserved egg mass was 1.04 g. Fat-body mass in both males and females decreases with the onset of the reproductive season. The age/size structure of the population varied from month to month, depending on recruitment of hatchlings. Reproduction in Leiocephalus psammodromus is similar to that of other tropical lizards in seasonal environments.

scholarly journals Breeding pattern of Oreochromis niloticus (Linnaeus, 1758) (Pisces: Cichlidae) versus native congeneric species, Oreochromis macrochir (Boulinger, 1912) in the upper Kabompo River, northwest of Zambia

2021 ◽  
Author(s):  
Arthertone Jere ◽  
Wilson Jere ◽  
Austin Mtethiwa ◽  
Daud Kassam
Keyword(s):  
Sex Ratio ◽  
Oreochromis Niloticus ◽  
Breeding Population ◽  
Cold Season ◽  
Biological Research ◽  
Congeneric Species ◽  
Wet Season ◽  
Males And Females ◽  
The Impact ◽  
Somatic Index

Investigating the determinants of reproductive biology of fishes is an essential component of biological research. Breeding pattern was investigated to determine the impact of exotic Oreochromis niloticus on the native congeneric Oreochromis macrochir in the upper Kabompo River. Gonado-somatic index and sex ratio was used to investigate the breeding pattern in both invaded (where O. niloticus is present) and uninvaded (where O. niloticus is absent) sections of the river. Oreochromis macrochir was the only native congeneric species found in both sections. Results showed that the overall gonado-somatic index means for both sexes of O. macrochir in both sections were similar. For O. niloticus in invaded section indicated all year reproduction though reduced spawning in cold season (May-June), but with increased spawning activity in wet season (February-March). In O. macrochir, males and females were found breeding in both dry and wet seasons only, as for cold season no reproduction was recorded. Sex ratio (females: males) was 1:1.3 and 1:1.7 for O. niloticus and O. macrochir respectively, and both significantly deviated from the sex ratio of 1:1 (ꭓ2=8.42 and 9.37; p<0.05). Oreochromis niloticus formed the most abundant fish caught 221(63.5%) than O. macrochir 127(36.5%). Our study has revealed that O. niloticus was able to spawn in all seasons with 23% higher breeding population than O. macrochir, which explains the suppression in the abundance. We expect O. niloticus to invade further downstream of the Kabompo River due to natural dispersion.

scholarly journals Pollution (Poly Aromatic Hydrocarbons and Heavy Metals) Evaluation in Soil of Selected Area of Kaduna Towns in Kaduna State

2019 ◽  
Vol 2 (1) ◽  
Keyword(s):  
Heavy Metals ◽  
Aromatic Hydrocarbons ◽  
Urban Areas ◽  
Pollution Index ◽  
Dry Season ◽  
Wet Season ◽  
Petroleum Resources ◽  
Polycyclic Aromatic ◽  
Pahs Concentration ◽  
Study Sites

The Polycyclic aromatic hydrocarbons (PAHs) and some heavy metals were analysis in the soil samples from urban areas of Kaduna state for their concentration and distribution. Naphthalene, acenaphthylene, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene, pyrene, chrysene, benzo(a)anthracene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a) pyrene, indeno(1,2,3-cd)perylene, benzo(ghi) perylene and dibenzo(a,h) anthracene were analyzed in three urban soils of Kaduna North, Alegbi and Kaduna South, at 0-15 cm and 16-30 cm depth in wet and dry seasons. After extraction using ultrasonication with hexane and dichloromethane and clean-up, PAHs concentration was measured using gas chromatography. The concentration of all the PAHs obtained ranged between 178.00 mg/g and 787.0 0 mg/g for wet season and 105.10 mg/g and 437.70 mg/g for dry season. The concentrations of PAHs were higher in the subsoil (15-30 cm depth) in the wet season than in the dry season while higher concentrations of all the PAHs were observed in topsoil than subsoil during the dry season. The concentration of PAHs followed the order Kaduna North > Kaduna South > Algabi during the wet season and Kaduna South > Algabi > Kaduna Nort during the dry season. The concentration values of all determined PAHs were below the target value of 1000 mg/g stipulated by Department of Petroleum Resources. The Cd, Cr, Cu and Pb levels in the soil from the study sites were higher than the corresponding control values. The degree of pollution of various metals using the graded standard of Nemero pollution index varied. The concentrations of the metals were found to be above the recommended limits given by USEPA/WHO. This could pose risks and hazards to human and the ecosystem through direct ingestion of contaminated soil

Spinosyns Delivered in Sugar Meals to Aedes aegypti and Aedes albopictus (Diptera: Culicidae): Acute Toxicity and Subacute Effects on Survival, Fecundity, and Fertility

2022 ◽  
Author(s):  
Abdullah A Alomar ◽  
Barry W Alto ◽  
Edward D Walker
Keyword(s):  
Acute Toxicity ◽  
Aedes Aegypti ◽  
Aedes Albopictus ◽  
Nutritive Value ◽  
Mosquito Control ◽  
Environmental Safety ◽  
Adult Mosquito ◽  
Hatch Rate ◽  
Median Lethal Concentrations ◽  
Males And Females

Abstract Sugar is an essential source of nutrition for adult mosquitoes to acquire energy. Toxic sugar bait (TSB) provides a promising method for mosquito control by incorporating toxins into artificial sources of sugar (i.e., toxic baits) presented to wild populations. Spinosyns comprise a family of bacterial secondary metabolites with a unique mode of action against the insect nervous system, an appealing environmental safety profile, and potential for incorporation into sugar baits. This research evaluated acute and subacute effects of spinosad (spinosyns A and D) and spinetoram (spinosyns J and L) in sugar meals on survival, fecundity, and fertility of Aedes aegypti and Aedes albopictus. Acute toxicity of spinosyns doubled from 24 to 48 h of assessment, revealing a relatively slow and cumulative action of the formulated spinosyns. Median lethal concentrations at 48 h were lower for spinetoram than for spinosad, lower for Ae. albopictus than Ae. aegypti, and lower for males than females. When exposed to subacute LC50 concentrations of spinosad and spinetoram for 24 h, survival of males and females of both species was diminished compared with controls, fecundity of females was increased, but fertility as measured by hatch rate of eggs was decreased. The formulations may have increased the nutritive value of the sugar meals thereby boosting fecundity, while toxifying embryos, reducing fertility. The inclusion of subacute effects of spinosyns allows assessment of the broader consequences of TSB for adult mosquito control.

Home-range and den use of the mahogany glider, Petaurus gracilis

2000 ◽  
Vol 27 (1) ◽  
pp. 49 ◽  
Author(s):  
Stephen M. Jackson
Keyword(s):  
Home Range ◽  
Dry Season ◽  
Home Ranges ◽  
Adjacent Area ◽  
Wet Season ◽  
Male And Female ◽  
Fragmented Habitat ◽  
Significant Difference ◽  
Socially Monogamous ◽  
Males And Females

The home-range of the mahogany glider was estimated, and its social behaviour examined, by following radio-collared animals over a two-year period within an area of continuous habitat and an adjacent area of fragmented habitat. The average home range within the continuous habitat was 19.25 ha for males and 20.34 ha for females, with male and female pairs occupying a combined area of 23.15 ha. In contrast, the average home range in the fragmented habitat was 11.05 ha for males and 6.80 ha for females, with a combined home-range of male and female pairs being 11.60 ha. The average overlap of the home ranges of paired males and females was 85.9%, compared with approximately 11% for non-paired individuals, which suggests that mahogany gliders are socially monogamous. For a total of 46 nights on which gliders were considered to behave normally for the entire night, the average foraging distance was 1506 m (range 590–3420 m) with no significant difference between males and females in either the continuous or fragmented habitat. There was, however, a significant difference in the distance individuals travelled during different times of the year, with longer distances being travelled during late dry season/wet season and shorter distances during the early to mid dry season. Mahogany gliders also travelled further when there was a high availability of nectar and pollen than when there was lower availability. A total of 83 dens (tree hollows) were recorded for the mahogany glider, with the poplar gum, Eucalyptus platyphylla, forest red gum, Eucalyptus tereticornis, and Clarkson's bloodwood, Corymbia clarksoniana, being most used.

Sign in / Sign up

Export Citation Format

Share Document